Field of the Invention
The present invention relates to a wire electric discharge machine controller having a wire electrode replacement function.
Description of the Related Art
In incorporating a wire electric discharge machine into a mass-production machining line of a manufacturing plant, a prolonged continuous operation is required to improve the productivity. In this case, a wire electric discharge system is employed comprising workpiece replacement means for automatically replacing workpieces. If various consumable parts of the wire electric discharge machine having reached their life limit require replacement, however, the continuous operation must be temporarily stopped and restarted after the consumable parts are manually replaced. This retards the prolonged, continuous automatic operation, thus hindering an improvement in the productivity.
Conventional techniques have been devised to detect the expiration of the life of a wire electrode of a wire electric discharge machine and the remaining lifetime of the wire electrode. According to these techniques, however, an indication to the effect that the replacement timing for the wire electrode is reached is displayed on a display device to urge an operator to replace the wire electrode.
Japanese Patent Application Laid-Open No. 2010-179377 discloses a technique for a wire electric discharge machine in which the remaining amount of a wire is detected based on a detected value of the wire tension. According to this technique, a machining program is analyzed to obtain a necessary wire length for workpiece machining before the machining, the necessity of wire bobbin replacement is determined by comparing the obtained wire length and the detected remaining amount of the wire, and the result of the determination is displayed on a display device.
Japanese Patent Application Laid-Open No. 2003-25155 discloses a wire electric discharge machine configured to calculate the remaining amount of a wire, calculate the consumption of the wire for each machining condition unit by analyzing a machining program, and report the points of wire cutting and wire electrode replacement by comparing the remaining amount and the consumption.
Japanese Patent Application Laid-Open No. 9-216129 discloses an electric discharge machine furnished with a workpiece handling robot for taking out a workpiece and a core, in which the workpiece handling robot is disposed outside a machining tank.
Japanese Patent Application Laid-Open No. 8-118151 discloses a wire electric discharge machine configured to automatically replace a head comprising a power feeder (electrode pin) and a wire guide. In this machine, the durable time of the power feeder is previously registered so that the head can be replaced with machining temporarily stopped when the durable time is exceeded by the operating time of the machine.
Japanese Patent Application Laid-Open No. 7-266137 discloses a wire electric discharge machine comprising a workpiece changer that is provided with drying means and rustproof means for machined workpieces.